Flexible display apparatus

ABSTRACT

A flexible display apparatus includes a substrate having a bending portion, a display over the substrate, and a cover over the substrate and covering the display. The cover includes a first film having a first surface and a second surface opposite the first surface, a second film over the first film, and an adhesive layer between the first film and the second film and attaching the first film to the second film. The first film includes at least one division line in at least some regions thereof in a direction from the first surface toward the second surface.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 15/596,929 filed on May 16, 2017, which claims priority under35 USC § 119 to Korean Patent Application No. 10-2016-0060905, filed onMay 18, 2016, in the Korean Intellectual Property Office, thedisclosures of which are incorporated herein in their entirety byreference.

BACKGROUND 1. Field

One or more embodiments relate to a flexible display apparatus.

2. Description of the Related Art

With the advances in information technologies, the market for displayapparatuses used as connecting media between users and information isgrowing. Accordingly, the use of display apparatuses has increased, andexamples of the display apparatuses include liquid crystal displays(LCD), organic light-emitting diode displays (OLED), electrophoreticdisplays (EPD), and plasma display panels (PDP).

Recently, there is a need for a flexible display panel that is bendablein various directions as well as a flat-panel display panel.

However, if a film having a low density is used in a bending portion ofa flexible display panel, the flexible display apparatus may be torn inthe bending portion.

SUMMARY

One or more embodiments include a flexible display apparatus including acover having a buffer film capable of efficiently absorbing an externalshock without being torn even in a bending portion.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to one or more embodiments, a flexible display apparatusincludes: a substrate having a bending portion; a display over thesubstrate; and a cover over the substrate and covering the display,wherein the cover includes: a first film having a first surface and asecond surface opposite the first surface; a second film over the firstfilm; and an adhesive layer between the first film and the second filmand attaching the first film to the second film, and the first filmincludes at least one division line in at least some regions thereof ina direction from the first surface toward the second surface.

The at least one division line may penetrate from the first surface tothe second surface of the first film.

The at least one division line may include two or more division lines,and the at least one division line may include n division lines thatdivide the first film into n+1 regions.

The at least one division line may be at a position corresponding to thebending portion.

The at least one division line may include two or more division linesthroughout the first film.

The at least one division line may include two or more division lines,and an interval between the two or more division lines at a positioncorresponding to the bending portion may be different from an intervalbetween the two or more division lines at other positions.

The interval between the two or more division lines at the positioncorresponding to the bending portion may be less than the intervalbetween the two or more division lines at the other positions.

A length of the at least one division line may be less than a thicknessof the first film.

The length of the at least one division line may be half the thicknessof the first film.

The first film may further include a healing agent.

When the first film is torn, a healing material discharged from thehealing agent may be cross-linked to a material constituting the firstfilm.

The first film may be a buffer film.

The first film may include an elastomer-based material.

The first film may include at least one selected from the groupconsisting of urethane, acrylate, and silicone.

The first film may include a plurality of air pores and have a foamdensity of about 0.3 g/cm³ to about 0.7 g/cm³.

The first film may have a thickness of about 50 μm to about 150 μm.

The at least one division line may include two or more division lines,and an interval between the two or more division lines may be in a rangefrom about 10 μm to about 1 mm.

The flexible display apparatus may further include a third film underthe first film, wherein the second film may be a light blocking film andthe third film may be a heat dissipation film.

The at least one division line may be formed from the first surfacetoward the second surface of the first film by a blanking process.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a schematic perspective view of a flexible display apparatusaccording to an embodiment;

FIG. 2 is a schematic cross-sectional view taken along line II-II′ ofFIG. 1, according to an embodiment;

FIG. 3A is a schematic cross-sectional view taken along line III-III′ ofFIG. 1, according to an embodiment;

FIG. 3B is a schematic cross-sectional view taken along line III-III′ ofFIG. 1, according to another embodiment;

FIG. 3C is a schematic cross-sectional view taken along line III-III′ ofFIG. 1, according to another embodiment;

FIG. 4 is a schematic cross-sectional view illustrating a case where acover of FIG. 3A is bent;

FIG. 5 is a schematic cross-sectional view of a cover according toanother embodiment;

FIG. 6 is a schematic cross-sectional view of a cover according toanother embodiment;

FIG. 7A is a schematic cross-sectional view of a cover according toanother embodiment;

FIG. 7B is a schematic cross-sectional view of a cover according toanother embodiment;

FIG. 8 is a schematic cross-sectional view of a cover according toanother embodiment;

FIG. 9A is a schematic cross-sectional view of a cover according toanother embodiment;

FIG. 9B is a schematic cross-sectional view of a cover according toanother embodiment; and

FIG. 10 is a schematic cross-sectional view of a cover according toanother embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the present description. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Expressions such as “at least one of” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

Various alterations and modifications may be made to embodiments, someof which will be illustrated in detail in the drawings and detaileddescription. The effects and features, and methods of achieving theeffects and features will become apparent from the embodiments describedbelow in detail with reference to the accompanying drawings. However,the inventive concept is not limited to the following embodiments andmay be realized in various forms.

It will be understood that although the terms “first”, “second”, etc.may be used herein to describe various components, these componentsshould not be limited by these terms. These components are only used todistinguish one component from another.

As used herein, the singular forms “a,” “an”, and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be understood that the terms “comprise”, “include”, and “have”used herein specify the presence of stated features or elements, but donot preclude the presence or addition of one or more other features orelements.

It will be understood that when a layer, region, or component isreferred to as being “formed on,” another layer, region, or component,it can be directly or indirectly formed on the other layer, region, orcomponent. That is, for example, intervening layers, regions, orcomponents may be present.

Sizes of elements in the drawings may be exaggerated for convenience ofexplanation. For example, since sizes and thicknesses of components inthe drawings are arbitrarily illustrated for convenience of explanation,the following embodiments are not limited thereto.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order.

FIG. 1 is a schematic perspective view of a flexible display apparatus1000 according to an embodiment, and FIG. 2 is a schematiccross-sectional view taken along line II-II′ of FIG. 1, according to anembodiment. FIG. 3A is a schematic cross-sectional view taken along lineIII-III′ of FIG. 1, according to an embodiment.

Referring to FIGS. 1 and 2, the flexible display apparatus 1000according to the embodiment may include a substrate 100, a display 200over the substrate 100, and a cover 500 over the substrate 100 andcovering the display 200.

The substrate 100 may include a flexible plastic material. For example,the substrate 100 may include polyethersulphone (PES), polyacrylate(PAR), polyetherimide (PEI), polyethylene naphthalate (PEN),polyethylene terephthalate (PET), polyphenylene sulfide (PPS),polyallylate, polyimide (PI), polycarbonate (PC), cellulose triacetate(TAC), or cellulose acetate propionate (CAP).

According to an embodiment, when the flexible display apparatus 1000 isa bottom-emission type display apparatus in which an image is realizedtoward the substrate 100, the substrate 100 may include a transparentmaterial. According to another embodiment, when the flexible displayapparatus 1000 is a top-emission type display apparatus in which animage is realized toward the display 200, the substrate 100 need notinclude a transparent material. In this case, the substrate 100 mayinclude a flexible opaque metal. According to another embodiment, whenthe substrate 100 is formed using a metal, the substrate 100 may includeat least one selected from the group consisting of iron, chromium,manganese, nickel, titanium, molybdenum, stainless steel (SUS), an Invaralloy, an Inconel alloy, and a Kovar alloy. Also, the substrate 100 mayinclude a metal foil.

The substrate 100 may include a flat portion F and at least one bendingportion B. The bending portion B is continuous to the flat portion F.FIG. 1 illustrates an example in which the substrate 100 includes a pairof bending portions B on both sides of the flat portion F. The pair ofbending portions B may have the same shape or may have different shapes.Also, the pair of bending portions B may have a constant curvature ormay have a varying curvature. However, embodiments of the presentdisclosure are not limited thereto. The bending portion B may bevariously formed. For example, the bending portion B may be formed onlyat one edge of the flat portion F, at all edges of the flat portion F,or inside the flat portion F.

The display 200 may be over the substrate 100 and realize an image. Thedisplay 200 may include a first display region D1 over the flat portionF and a second display region D2 over the at least one bending portionB. The first display region D1 may be continuous to the second displayregion D2. The first display region D1 and the second display region D2may form a single screen or different screens.

The display 200 may include, for example, a thin film transistor TFT andan organic light-emitting device OLED, hereinafter the TFT and the OLED,respectively. However, embodiments of the present disclosure are notlimited thereto. The display 200 may include various types of displayelements.

Hereinafter, the display 200 in the first display region D1 will bedescribed in more detail with reference to FIG. 2.

A buffer layer 110 may be formed over the substrate 100. The bufferlayer 110 may prevent impurity ions from diffusing into the display 200,may prevent penetration of moisture or outside air, and may serve as abarrier layer and/or a blocking layer for planarizing the surface of thesubstrate 100. For example, the buffer layer 110 may include aninorganic material, such as silicon oxide, silicon nitride, siliconoxynitride, aluminum oxide, aluminum nitride, titanium oxide, titaniumnitride, or the like, an organic material, such as polyimide, polyester,acryl, or the like, or any laminate including two or more of thematerials listed above.

A TFT may be formed over the substrate 100. The TFT may include asemiconductor layer A, a gate electrode G, a source electrode S, and adrain electrode D. FIG. 2 illustrates a top gate type TFT including thesemiconductor layer A, the gate electrode G, the source electrode S, andthe drain electrode D in this stated order, but embodiments of thepresent disclosure are not limited thereto. Various types of the TFT,such as a bottom gate type TFT, may be used.

The semiconductor layer A may include an organic semiconductor or aninorganic semiconductor such as silicon. Also, the semiconductor layer Ahas a source region, a drain region, and a channel region therebetween.For example, in a case where the semiconductor layer A is formed usingamorphous silicon, an amorphous silicon layer may be formed on an entiresurface of the substrate 100 and crystallized to form a polycrystallinesilicon layer. The polycrystalline silicon layer may be patterned. Then,impurities may be doped into both edges of the polycrystalline siliconlayer, i.e., the source region and the drain region, to thereby form thesemiconductor layer A including the source region, the drain region, andthe channel region therebetween.

After the semiconductor layer A is formed, a gate insulating film 210may be formed on the entire surface of the substrate 100 and over thesemiconductor layer A. The gate insulating film 210 may include asingle-layered or multi-layered film including an inorganic materialsuch as silicon oxide or silicon nitride. The gate insulating film 210may insulate the semiconductor layer A from the gate electrode Gthereover.

The gate electrode G may be formed in a certain region over the gateinsulating film 210. The gate electrode G is connected to a gate line(not illustrated) through which a TFT on/off signal is applied. The gateelectrode G may include at least one selected from the group consistingof molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver(Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium(Ir), chromium (Cr), lithium (Li), calcium (Ca), titanium (Ti), tungsten(W), and copper (Cu), but embodiments of the present disclosure are notlimited thereto. The gate electrode G may include various materials bytaking into account a design condition.

After the gate electrode G is formed, an interlayer insulating film 230may be formed on the entire surface of the substrate 100 in order for aninsulation between the gate electrode G and the source electrode S andan insulation between the gate electrode G and the drain electrode D.

The interlayer insulating film 230 may include an inorganic material.For example, the interlayer insulating film 230 may include metal oxideor metal nitride. Specifically, the inorganic material may includesilicon oxide (SiO₂), silicon nitride (SiN_(x)), silicon oxynitride(SiON), aluminum oxide (Al₂O₃), titanium oxide (TiO₂), tantalum oxide(Ta₂O₅), hafnium oxide (HfO₂), or zinc oxide (ZrO₂).

The interlayer insulating film 230 may include a single-layered ormulti-layered film including an inorganic material such as silicon oxide(SiO_(x)) or silicon nitride (SiN_(x)). In some embodiments, theinterlayer insulating film 230 may have a double structure of SiO_(x)and SiN_(y), or SiN_(x) and SiO_(y).

A source electrode S and a drain electrode D are formed over theinterlayer insulating film 230. Specifically, the interlayer insulatingfilm 230 and the gate insulating film 210 are formed to expose thesource region and the drain region of the semiconductor layer A, and thesource electrode S and the drain electrode D are formed to contact theexposed source region and the exposed drain region of the semiconductorlayer A.

Each of the source electrode S and the drain electrode D may have asingle-layered or multi-layer structure including at least one selectedfrom the group consisting of aluminum (Al), platinum (Pt), palladium(Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium(Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca),molybdenum (Mo), titanium (Ti), tungsten (W), and copper (Cu).

The TFT is electrically connected to the OLED to apply an OLED drivingsignal to the OLED. In order to protect the TFT, the TFT may be coveredwith a planarization film 250.

The planarization film 250 may include an inorganic insulating filmand/or an organic insulating film. The inorganic insulating film mayinclude SiO₂, SiN_(x), SiON, Al₂O₃, TiO₂, Ta₂O₅, HfO₂, ZrO₂, BST, orPZT, and the organic insulating film may include a general-purposepolymer (PMMA, PS), a polymer derivative having a phenol-based group, anacryl-based polymer, an imide-based polymer, an arylether-based polymer,an amide-based polymer, a fluorine-based polymer, a p-xylene-basedpolymer, a vinylalcohol-based polymer, and any blend thereof. Also, theplanarization film 250 may include a complex laminate of an inorganicinsulating film and an organic insulating film.

The OLED may be over the planarization film 250. The OLED may include afirst electrode 281, an intermediate layer 283 including an organicemission layer, and a second electrode 285. Holes and electrons, whichare respectively injected from the first electrode 281 and the secondelectrode 285 of the OLED, may recombine in the organic emission layerof the intermediate layer 283 to generate light.

The first electrode 281 is formed over the planarization film 250 and iselectrically connected to the drain electrode D through a contact holeof the planarization film 250. However, embodiments of the presentdisclosure are not limited to the case where the first electrode 281 iselectrically connected to the drain electrode D. The first electrode 281may be electrically connected to the source electrode S to receive theOLED driving signal.

The first electrode 281 may be a reflective electrode and may include areflective film and a transparent or translucent electrode layer overthe reflective film. The reflective film may include Ag, Mg, Al, Pt, Pd,Au, Ni, Nd, Ir, Cr, or any compound thereof. The transparent ortranslucent electrode layer may include at least one selected from thegroup consisting of indium tin oxide (ITO), indium zinc oxide (IZO),zinc oxide (ZnO), indium oxide (In₂O₃), indium gallium oxide (IGO), andaluminum zinc oxide (AZO).

The intermediate layer 283 may include an organic emission layer.Alternatively, the intermediate layer 283 may include an organicemission layer and may further include at least one selected from amonga hole injection layer (HIL), a hole transport layer (HTL), an electrontransport layer (ETL), and an electron injection layer (EIL). Theembodiment of the present disclosure is not limited thereto and theintermediate layer 283 may include an organic emission layers and mayfurther include various function layers.

The second electrode 285 is formed over the intermediate layer 283. Thesecond electrode 285 forms an electric field with the first electrode281 so that light is emitted from the intermediate layer 283. The firstelectrode 281 may be patterned at each pixel and the second electrode285 may be formed so that a common voltage is applied to the entirepixels.

The second electrode 285 facing the first electrode 281 may be atransparent or translucent electrode and may be a metal thin film thathas a low work function and includes Li, Ca, LiF/Ca, LiF/Al, Al, Ag, Mg,or any compound thereof. Also, an auxiliary electrode layer or a buselectrode may be further formed over the metal thin film. The auxiliaryelectrode layer or the bus electrode may include a material for forminga transparent electrode, such as ITO, IZO, ZnO, or In₂O₃.

Accordingly, the second electrode 285 may transmit light emitted fromthe organic emission layer (not illustrated) included in theintermediate layer 283. That is, the light emitted from the organicemission layer (not illustrated) may be reflected directly or by thefirst electrode 281 including a reflective electrode and then emittedtoward the second electrode 285.

However, the display 200 according to the embodiment is not limited tothe top-emission type display, and the display 200 may be abottom-emission type display in which light emitted from the organicemission layer (not illustrated) is emitted toward the substrate 100. Inthis case, the first electrode 281 may be a transparent or translucentelectrode, and the second electrode 285 may be a reflective electrode.Also, the display 200 according to the embodiment may be adouble-side-emission type display in which light is emitted in twodirections, that is, frontward and rearward.

Alternatively, the first electrode 281 may be patterned, for example, ateach pixel. The display 200 may further include a pixel defining film270 over the first electrode 281. The pixel defining film 270 mayinclude an opening 270 a extending to and exposing the first electrode281. The intermediate layer 283 may be formed corresponding to theopening 270 a and electrically connected to the first electrode 281. Thepixel defining film 270 may include at least one organic insulatingmaterial selected from the group consisting of polyimide, polyamide, anacryl resin, benzocyclobutene, and a phenol resin and may be formed byspin coating or the like.

The cover 500 may be over the substrate 100 so as to cover the display200 disposed over the substrate 100.

Alternatively, the cover 500 may include a cover glass containing aglass material. Any material may be used as the cover 500 as long as thematerial is attachable to the upper portion of the substrate 100 so asto cover the display 200.

As illustrated in FIG. 3A, a cover 500 a of the flexible displayapparatus 1000 according to the embodiment may include a first film 510,a second film 530, and an adhesive layer 520 between the first film 510and the second film 530 and attaching the first film 510 to the secondfilm 530.

The first film 510 may include a first surface 510 a and a secondsurface 510 b opposite the first surface 510 a. The first film 510 mayinclude division lines L in at least some regions thereof in a directionfrom the first surface 510 a toward the second surface 510 b. Thedivision lines L may be cuts in the first film 510.

Alternatively, the division lines L are illustrated in FIG. 3A as beingformed from the first surface 510 a to the second surface 510 b, butthis is merely an example. An embodiment in which the division lines Lare partially formed will be described later in detail.

In the display apparatus 1000 according to the embodiment, the divisionlines L penetrating the first film 510 may be formed from the firstsurface 510 a toward the second surface 510 b. That is, the first film510 may be divided into two regions by one division line L.

The first film 510 illustrated in FIG. 3A includes seven division linesL, but the number of division lines L is not limited thereto. One ormore division lines L, sometime called at least one division line L, maybe formed from the first surface 510 a toward the second surface 510 bwithout limitations.

Alternatively, the division lines L included in the first film 510 maybe formed by a blanking process. The blanking process could be cuttingprocess for obtaining desired shape.

In the display apparatus 1000 according to the embodiment, n divisionlines L may be formed in the first film 510 by a blanking process topenetrate from the first surface 510 a to the second surface 510 b.Accordingly, the first film 510 may be divided into n+1 regions.

Since a plurality of division lines L are formed in the first film 510to penetrate from the first surface 510 a to the second surface 510 b,the first film 510 may be divided by the division lines L even when thecover 500 is bent in a bending portion B as illustrated in FIG. 4.Accordingly, even when tensile stress is applied to the first film 510by the bending, a risk of tearing may be reduced.

FIG. 3B is a schematic cross-sectional view taken along line III-III′ ofFIG. 1, according to another embodiment, and FIG. 3C is a schematiccross-sectional view taken along line III-III′ of FIG. 1, according toanother embodiment. In FIGS. 3B and 3C, the same reference numerals asthose used in FIG. 3A refer to the same members, and redundantdescriptions thereof will be omitted for conciseness.

A cover 500 b of the flexible display apparatus according to theembodiment of FIG. 3B may include a first film 510, a second film 530,and an adhesive layer 520 between the first film 510 and the second film530 and attaching the first film 510 to the second film 530. The secondfilm 530 may include a first surface 530 a, a second surface 530 b, anddivision lines L penetrating the second film 530 in a direction from thefirst surface 530 a toward the second surface 530 b.

Like the division lines L in the first film 510 of FIG. 3A, the numberand positions of division lines L in the second film 530 are notparticularly limited. n division lines L may be formed in at least someregions of the second film 530 to thereby divide the second film 530into n+1 regions.

Alternatively, as illustrated in FIG. 3C, each of a first film 510 and asecond film 530 of a cover 500 c may include division lines L.

FIG. 3C illustrates the cover 500 c in which the first film 510 and thesecond film 530 include the same number of division lines L at the samepositions, but the cover 500 c is not limited thereto. The first film510 and the second film 530 may include one or more division lines L indifferent number at different positions.

Alternatively, in FIGS. 3A to 3C, the first film 510 may be a bufferfilm. That is, the first film 510 may have an elastic force and mayabsorb a shock when the flexible display apparatus 1000 is deformed orreceives an external force, thereby preventing the cover 500 from beingdamaged.

Alternatively, in a case where the first film 510 is a buffer film, thefirst film 510 may include an elastomer-based material. For example, thefirst film 510 may include at least one selected from the groupconsisting of urethane, acrylate, and silicone.

In a case where the first film 510 is a buffer film, as a density of thefirst film 510 becomes higher, a deformation rate of the first film 510is reduced and it is more likely that the first film 510 will be tornwhen the flexible display apparatus 1000 is deformed.

Accordingly, in the flexible display apparatus 1000 according to theembodiment, the first film 510 may have an elastic force so as to serveas the buffer film and may include a plurality of air pores so as toprevent the cover 500 from being damaged even when an external force isapplied to the cover 500. Alternatively, the first film 510 may have afoam density of about 0.3 g/cm³ to about 0.7 g/cm³.

Alternatively, the first film 510 may have a thickness of about 50 μm toabout 150 μm.

Alternatively, the adhesive layer 520 may include any material as longas the material attaches the first film 510 to the second film 530. Theadhesive layer 520 may have a thickness of about 20 μm to about 50However, the thicknesses of the first film 510 and the adhesive layer520 are not limited to the above-mentioned values.

Alternatively, in FIGS. 3A to 3C, the second film 530 may be a lightblocking film. That is, the second film 530 may block light so as toprevent lower components from being exposed to the outside through thecover 500. Hence, the second film 530 may have a dark color.Alternatively, the light blocking film 530 may include division lines Lpenetrating the light blocking film 530 in a direction from the firstsurface 530 a toward the second surface 530 b.

Alternatively, in FIGS. 3A to 3C, the second film 530 may be a lowerprotective film. The lower protective film protects lower components ofthe cover 500 and the substrate 100, in which the display 200 isdisposed, from an external force. Alternatively, the lower protectivefilm 530 may include division lines L penetrating the lower protectivefilm 530 in a direction from the first surface 530 a toward the secondsurface 530 b.

In the related art, the flexible display apparatus may be bent in thebending portion as described above, and the first film and/or the secondfilm included in the cover may receive compression stress and/or tensilestress in a bending portion. Consequently, the first film and/or thesecond film may be torn due to the tensile stress in the bendingportion. In particular, when the first film is a buffer film, the firstfilm may include a plurality of air pores and have a foam density rangeof about 0.3 g/cm³ to about 0.7 g/cm³. Accordingly, a probability ofbeing torn in the bending portion increases.

On the contrary, in the flexible display apparatus 1000 according to theembodiment, since the first film 510 and/or the second film 530 includedivision lines L in at least some regions thereof, the first film 510and/or the second film 530 divided by the division lines L is not torn,but a gap therein is opened with respect to the division lines L.Accordingly, even when the bending occurs, the probability that thefirst film 510 and/or the second film 530 will be torn is minimized,thereby improving the reliability of the cover 500 and the flexibledisplay apparatus 1000.

FIG. 4 is a schematic cross-sectional view illustrating a case where thecover 500 a of FIG. 3A is deformed. As illustrated in FIG. 4, in a casewhere the first film 510 includes division lines L penetrating the firstfilm 510 in a direction from the first surface 510 a toward the secondsurface 510 b, even when the bending occurs, the first film 510 is nottorn, but a gap is naturally opened between regions having already beendivided with respect to the division lines L, thereby obtaining theeffect that the first film 510 is not torn.

FIG. 5 is a schematic cross-sectional view of a cover according toanother embodiment, and FIG. 6 is a schematic cross-sectional view of acover according to another embodiment. In FIGS. 5 and 6, the samereference numerals as those used in FIG. 3A refer to the same members,and redundant descriptions thereof will be omitted for conciseness.

The cover 500 according to the embodiment may include a first film 510having division lines L only in a bending portion B. Alternatively, thefirst film 510 may be a buffer film. In this case, the first film 510may include an elastomer-based material having an elastic force toabsorb a shock. Also, the first film 510 may include a plurality of airpores and may have a low density accordingly.

In the flexible display apparatus according to the embodiment, sincetensile stress and compression stress applied to the first film 510 aremaximum in the bending portion B, the probability that the first film510 having a low forming density will be torn at the bending portion Bis highest. Accordingly, the first film 510 may include division lines Lonly in the bending portion B.

As described above with reference to FIG. 3A, the division lines L maypenetrate from the first surface 510 a toward the second surface 510 bof the first film 510 in the bending portion B.

However, the number and positions of division lines L are not limited tothe example illustrated in FIG. 5. Alternatively, the division lines Lmay be formed only in the bending portion B of the second film 530, ormay be formed in both the bending portion of the first film 510 and thebending portion of the second film 530.

Alternatively, in a case where the division lines L are formed in thebending portions B of the first film 510 and the second film 530, thenumber and positions of division lines L may be equally or differentlyformed.

Alternatively, as illustrated in FIG. 6, a gap between the divisionlines L in the bending portion B of the first film 510 may be differentfrom a gap between the division lines L in the other portions of thefirst film 510.

The gap between the division lines L may be narrow (less) in the bendingportion B having maximum tensile stress and compression stress and maygradually increase as a distance from the bending portion B increases.

Since the gap between the division lines L is narrow (small) in thebending portion B, the first film 510 is divided into more regions and aflexibility thereof is improved even when the bending occurs, therebyreducing the probability that the first film 510 will be torn.

The number and positions of division lines L are not limited to theexample illustrated in FIGS. 5 and 6. Alternatively, the division linesL may be formed only in the bending portion B of the second film 530, ormay be formed in both the bending portion of the first film 510 and thebending portion of the second film 530.

Alternatively, in a case where the division lines L are formed in thebending portions B of the first film 510 and the second film 530, thenumber and positions of division lines L may be equally or differentlyformed.

FIG. 7A is a schematic cross-sectional view of a cover 500 according toanother embodiment. In FIG. 7A, the same reference numerals as thoseused in FIG. 3A refer to the same members, and redundant descriptionsthereof will be omitted for conciseness.

In the cover 500 according to the embodiment, one or more division linesL may be formed from a first surface 510 a toward a second surface 510 bof a first film 510. A length of the division line L may be less than athickness of the first film 510.

That is, the division line L does not completely penetrate the firstfilm 510 from the first surface 510 a to the second surface 510 b, andthe division line L may be formed from the first surface 510 a towardthe second surface 510 b and has a length less than the thickness of thefirst film 510 so that the division line L does not reach the secondsurface 510 b.

Alternatively, the division line L may be formed up to a positioncorresponding to half the thickness of the first film 510.

In a case where the length of the division line L is less than thethickness of the first film 510, the first film 510 is not completelydivided by the division line L, but the first film 510 may be openedwith respect to the division line L.

Accordingly, when the cover 500 is bent in the bending portion B, thefirst film 510 is not torn to thereby improve the reliability of thecover 500 and the flexible display apparatus.

As illustrated in FIG. 4, when the bending occurs in the bending portionB, the second surface 510 b of the first film 510 receives a compressionforce and a contraction force, and the first surface 510 a opposite thesecond surface 510 b of the first film 510 receives a stretching forceand a tensile force.

It is more likely that a region close to the first surface 510 a of thefirst film 510 receiving the tensile force will be torn, as compared toa region close to the second surface 510 b of the first film 510receiving the contraction force. Accordingly, as illustrated in FIG. 7A,the division lines L may be partially formed only in the region close tothe first surface 510 a of the first film 510.

FIG. 7B is a schematic cross-sectional view of a cover 500 according toanother embodiment. In FIG. 7B, the same reference numerals as thoseused in FIG. 3A refer to the same members, and redundant descriptionsthereof will be omitted for conciseness.

Alternatively, the bending may occur in the bending portion B inopposite direction as shown in FIG. 4, thus the second surface 510 b ofthe first film 510 receives a tensile force, and the first surface 510 areceives a compression force.

In the cover 500 according to the embodiment, one or more division linesL may be formed from a second surface 510 b toward a first surface 510 aof a first film 510. A length of the division line L may be less than athickness of the first film 510.

However, the number and positions of division lines L are not limited tothe examples illustrated in FIGS. 7A and 7B. Alternatively, the divisionlines L may be formed in some regions of the second film 530, or may beformed in some regions of both the first film 510 and the second film530.

Alternatively, in a case where the division lines L are formed in someregions of both the first film 510 and the second film 530, the numberand positions of division lines L may be equally or differently formed.

Alternatively, the division line L may be formed up to a positioncorresponding to half the thickness of the first film 510 and/or thesecond film 530, or may be formed only in the bending portion B.

Alternatively, the division line L may be formed up to a positioncorresponding to half the thickness of the first film 510 and/or thesecond film 530. A gap between the division lines L may be narrow in thebending portion B receiving a high tensile force and a high compressionforce and may be wide in the other portions except for the bendingportion B.

FIG. 8 is a schematic cross-sectional view of a cover 500 according toanother embodiment. In FIG. 8, the same reference numerals as those usedin FIG. 3A refer to the same members, and redundant descriptions thereofwill be omitted for conciseness.

In the cover 500 of the flexible display apparatus according to theembodiment, a first film 510 may include one or more division lines Land one or more healing agents 600.

As illustrated in FIG. 8, the healing agent 600 may include a pluralityof grains and may be included in the first film 510. However, the numberand shape of healing agents 600 are not limited thereto.

When the first film 510 is unexpectedly torn in a bending process of theflexible display apparatus, the healing agents 600 included in the firstfilm 510 may be decomposed to discharge healing materials. These healingmaterials are cross-linked to a material constituting the first film 510and have an effect that can self-heal the torn first film 510.

Therefore, the healing agent 600 is a grain including a material that iscross-linked to the material constituting the first film 510, and aheating material is confined in the grain in a normal condition. Whenthe first film 510 is torn, the healing agent 600 is decomposed todischarge the healing material. The healing material is cross-linked tothe material constituting the first film 510, so that the torn portionof the first film 510 is attached again.

FIGS. 9A and 9B are schematic cross-sectional views of covers 500according to another embodiment, and FIG. 10 is a schematiccross-sectional view of a cover 500 according to another embodiment. InFIGS. 9A, 9B, and 10, the same reference numerals as those used in FIGS.3A to 3C refer to the same members, and redundant descriptions thereofwill be omitted for conciseness.

As illustrated in FIGS. 9A and 9B, the cover 500 according to theembodiment may include a first film 510, a second film 530 over thefirst film 510, and a third film 540 under the first film 510. Thesecond film 530 may be attached to a first surface 510 a of the firstfilm 510 by an adhesive layer 520, and the third film 540 may beattached to a second surface 510 b of the first film 510 by an adhesivelayer 520.

Alternatively, the first film 510, the second film 530, and the thirdfilm 540 may be respectively a buffer film, a light blocking film, and aheat dissipation film.

Alternatively, the first film 510, the second film 530, and the thirdfilm 540 may be respectively a buffer film, a light blocking film, and ashielding film.

Alternatively, the first film 510, the second film 530, and the thirdfilm 540 may be respectively a buffer film, a lower protective film, anda heat dissipation film.

As illustrated in FIG. 9A, when the first film 510 is a buffer film, thefirst film 510 includes a plurality of air pores. Thus, only the firstfilm 510 having the highest probability of being torn in the bendingprocess may include division lines L.

Alternatively, as illustrated in FIG. 9B, the second film 530 serving asthe light blocking film or the lower protective film may includedivision lines L, and the third film 540 serving as the heat dissipationfilm or the shielding film may include division lines L.

Although FIG. 9B illustrates the cover 500 in which all the first tothird films 510, 530, and 540 include the division lines L, embodimentsof the present disclosure are not limited thereto. Any cover in which atleast one of the first to third films 510, 530, and 540 includes thedivision lines L is applicable as embodiments of the present disclosure.

Alternatively, as illustrated in FIG. 10, the cover 500 may include afirst film 510, a second film 530 and a fourth film 550 over the firstfilm 510, and a third film 540 and a fifth film 560 under the first film510.

The second film 530 may be attached to a first surface 510 a of thefirst film 510 by an adhesive layer 520, and the third film 540 may beattached to a second surface 510 b of the first film 510 by an adhesivelayer 520. The fourth film 550 may be attached to the second film 530 byan adhesive layer 520, and the fifth film 560 may be attached to thefourth film 550 by an adhesive layer 520.

Alternatively, the first film 510, the second film 530, the third film540, the fourth film 550, and the fifth film 560 may be respectively abuffer film, a light blocking film, a heat dissipation film, a lowerprotective film, and a shielding film.

In this case, since the first film 510 serving as the buffer filmincludes a plurality of air pores so as to absorb an external shock, thefirst film 510 has a low density and has the highest probability ofbeing torn. Thus, the first film 510 may include the division lines L asillustrated in FIG. 10.

However, embodiments of the present disclosure are not limited thereto.Any cover in which at least one of the first to fifth films 510, 530,540, 550, and 550 includes the division lines L is applicable asembodiments of the present disclosure.

According to one or more embodiments, the buffer film is not torn evenin the bending portion.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A flexible display apparatus comprising: asubstrate having a bending portion; a display over the substrate; and acover over the substrate and covering the display, wherein the covercomprises: a first film having a first surface and a second surfaceopposite the first surface; a second film over the first film; and anadhesive layer between the first film and the second film and attachingthe first film to the second film, and the first film comprises at leastone division line in at least some regions thereof in a direction fromthe first surface toward the second surface, wherein the at least onedivision line penetrates from the first surface to the second surface ofthe first film, wherein the cover is bent towards the first film suchthat tensile stress is applied to the first film.
 2. The flexibledisplay apparatus of claim 1, wherein the at least one division linecomprises two or more division lines, and the at least one division linecomprises n division lines that divide the first film into n+1 regions.3. The flexible display apparatus of claim 1, wherein the at least onedivision line is at a position corresponding to the bending portion. 4.The flexible display apparatus of claim 1, wherein the at least onedivision line comprises two or more division lines throughout the firstfilm.
 5. The flexible display apparatus of claim 1, wherein the at leastone division line comprises two or more division lines, and an intervalbetween the two or more division lines at a position corresponding tothe bending portion is different from an interval between the two ormore division lines at other positions.
 6. The flexible displayapparatus of claim 5, wherein the interval between the two or moredivision lines at the position corresponding to the bending portion isless than the interval between the two or more division lines at theother positions.
 7. The flexible display apparatus of claim 1, whereinthe first film further comprises a healing agent.
 8. The flexibledisplay apparatus of claim 7, wherein, when the first film is torn, ahealing material discharged from the healing agent is cross-linked to amaterial constituting the first film.
 9. The flexible display apparatusof claim 1, wherein the first film is a buffer film.
 10. The flexibledisplay apparatus of claim 9, wherein the first film comprises anelastomer-based material.
 11. The flexible display apparatus of claim10, wherein the first film comprises at least one selected from thegroup consisting of urethane, acrylate, and silicone.
 12. The flexibledisplay apparatus of claim 9, wherein the first film comprises aplurality of air pores and has a foam density of about 0.3 g/cm3 toabout 0.7 g/cm3.
 13. The flexible display apparatus of claim 9, whereinthe first film has a thickness of about 50 μm to about 150 μm.
 14. Theflexible display apparatus of claim 1, wherein the at least one divisionline comprises two or more division lines and an interval between thetwo or more division lines is in a range from about 10 μm to about 1 mm.15. The flexible display apparatus of claim 1, further comprising athird film under the first film, wherein the second film is a lightblocking film and the third film is a heat dissipation film.
 16. Theflexible display apparatus of claim 1, wherein the at least one divisionline is formed from the first surface toward the second surface of thefirst film by a blanking process.